In general, when a sewage pipe laid under the ground is used for a long period of time, soil sediment, sludge, foreign material are deposited at interior of the sewage pipe, so that it is necessary to remove the deposited sediment, sludge and foreign material and clean the sewage pipe.
Further, the sewage pipe laid under the ground will be deteriorated with elapse of times, so that cracks and defects at joint portions of the sewage pipes are liable to occur. In particular, in a case where the sewage pipe is a Hume pipe, a bore or hole is liable to be formed due to erosion of the pipe body. Therefore, the interior of the sewage pipe is required to be periodically inspected and repaired, or the sewage pipe per se is required to be replaced by new one.
As described above, when the sewage pipe is subjected to various workings such as cleaning, inspection, repairing, replacement or the like, various equipments and instruments for the workings are conveyed into the sewage pipe, and workers would access into the sewage pipe to perform the working. Therefore, it is obliged for the sewage system containing the objective sewage pipe to be stopped in use.
As a countermeasure for solving the afore-mentioned problems, for example, a sewage by-pass or circulation discharging apparatus for sewage pipe works is well known as disclosed in Japanese Utility Model Publication No. HEI 6-13890.
The conventional sewage by-pass discharging apparatus for working the sewage pipe, as shown in FIG. 15, has a structure in which a portion 1a between a first manhole 2 and a second manhole 3 of the sewage pipe 1 is specifically provided as the working area, and a stop cock 4 is respectively provided to both an upstream side portion 1b and a downstream side portion 1c of the sewage pipe 1 laid in the working area 1a thereby to prevent the sewage or the like from flowing into the sewage pipe 1a laid in the working area la.
Further, a suction pipe 6 of a pump 5 disposed on the ground is connected to the upstream side portion 1b, while a delivery pipe 7 of the pump 5 is connected to the downstream side portion 1c, whereby the sewage or the like accumulated at upstream side from the working area flows toward the downstream side through bypassing the working area.
According to the sewage by-pass discharging apparatus for working the sewage pipe as described above, even if the sewage system is utilized as usual, the sewage would not flow into the sewage pipe laid in the working area. Therefore, the workings such as cleaning, inspection, repairing, replacement or the like for the sewage pipe laid in the working area can be performed while the sewage system is utilized as usual.
However, in actual, a plurality of drain pipes are connected to the sewage pipe laid between the first manhole 2 and the second manhole 3, and the drain pipes are connected to drain pits provided at respective homes of residents, so that the sewage or the like discharged from a plurality of the homes would flow into the sewage pipe laid in the working area.
Due to this situation, the respective residents of which the drain pit is connected to the sewage pipe laid in the working area are obliged to stop utilizing the sewage system during the working for the sewage pipe.
Therefore, an object of the present invention is to provide a sewage by-pass discharging apparatus for sewage pipe works capable of achieving various workings such as cleaning, inspection, repairing, replacement or the like for the sewage pipe while being maintained in a state where the respective residents can utilize the sewage system as usual.